The present disclosure generally relates to the art of thermal torches or cutting bars and more particularly relates to consumable thermal torches or lances. The one or more embodiments described herein are particularly applicable for use in conjunction with an oxygen-fed cutting torch used for cutting, boring, burning and/or the like of hard base materials. However, it will be appreciated that the present disclosure has broader applications and may be advantageously employed in other environments and applications.
Conventional cutting torches or thermic lances are well known in the art as represented by U.S. Pat. Nos. 5,000,426; 4,660,807; 4,114,863; 4,416,444; and 3,921,542. Each of these patents generally teaches the use of a first or outer tube through which is fed an oxidizing gas such as oxygen. The oxidizing gas is ignited in any known manner. For example, an electric arc may be used to initiate the combustion process. The outer tube may receive a second or inner tube, and/or a set of consumable metallic rods. When used, gas passages are defined within the inner tube and/or between the rods and tubes to convey the oxidizing gas from a gas supply connected at one end to a combustion end of the cutting torch. The volatile nature of the combustion is used to pierce hard base materials as desired, such as cast iron, steel, concrete, or rock, for example. As the combustion process proceeds, the torch is consumed and therefore must be periodically replaced.
One factor in the design or construction of consumable cutting torches is the length of time between replacement of the cutting torches (i.e., the useful life of the cutting torch). Another factor is the effectiveness of the cutting operation. Still another factor is the expense and/or ease of manufacture of such cutting torches. All of these factors, and others, are typically considered in evaluating efficiency, performance, and effectiveness of operation of a consumable cutting torch. Still another performance characteristic that is important to consider when developing a cutting torch is the amount of “splatter” produced by the cutting torch. The cutting torch taught by the above-referenced '863 patent has been effective in reducing such “splatter” associated with a cutting operation. In particular, the tube within a tube design, having thermo rods disposed in the inner tube, has proved to be highly successful in concentrating the thermic reaction. It is believed that the inner and outer tubes define a gas envelope that confines the splatter associated with the cutting operation. As discussed in the '863 patent, the tubes can be locked against relative axial movement through the use of plural detents (a type of cooperating structure) that extend radially inward from the outer tube toward the outer periphery of the inner tube.
Notwithstanding the commercial success of previous consumable cutting torches, there is always a desire to provide improved consumable cutting torches that provide increases in efficiency, performance and/or effectiveness. Moreover, there is always a need for improved consumable cutting torches that reduce splatter. Still further, there is always a need for improved consumable cutting torches that are easier and/or less expensive to manufacture.